8210 hangs

I have finally found an eeprom that worked a treat for my 8210. It worked for a few days then hung and now displays "Contact Service". I then re-flashed with same MCU, PPM and eeprom. It worked but I wonder when it will hang itself again. Eeprom Tools won't work for me to find out whether it is software or hardware problem - it doesn't recognise the phone is connected.

Any ideas???

Use Eeprom tools v4.0 and configure like the picture! Click the test button after it reads! Make sure you use the correct COM port too!;)